* ext/psych/lib/psych/visitors/emitter.rb: sending emit options to

  YAML emitter. [ruby-core:28318]
* ext/psych/emitter.c: updating documentation about emit options
* ext/psych/lib/psych/core_ext.rb: ditto
* ext/psych/lib/psych.rb (dump): passing emit options to emitter.
* ext/psych/lib/psych/nodes/node.rb: ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@28573 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

5 files changed, 30 insertions, 8 deletions

diff --git a/ext/psych/emitter.c b/ext/psych/emitter.c
index 0400f7e9ba..189b865ea3 100644
--- a/ext/psych/emitter.c
+++ b/ext/psych/emitter.c
@@ -435,7 +435,8 @@ static VALUE canonical(VALUE self)
 
 /* call-seq: emitter.indentation = level
  *
- * Set the indentation level to +level+.
+ * Set the indentation level to +level+.  The level must be less than 10 and
+ * greater than 1.
  */
 static VALUE set_indentation(VALUE self, VALUE level)
 {
diff --git a/ext/psych/lib/psych.rb b/ext/psych/lib/psych.rb
index c1feff8e3a..ba4a683974 100644
--- a/ext/psych/lib/psych.rb
+++ b/ext/psych/lib/psych.rb
@@ -155,11 +155,29 @@ module Psych
   end
 
   ###
-  # Dump Ruby object +o+ to a YAML string using +options+.
+  # call-seq:
+  #   Psych.dump(o)               -> string of yaml
+  #   Psych.dump(o, options)      -> string of yaml
+  #   Psych.dump(o, io)           -> io object passed in
+  #   Psych.dump(o, io, options)  -> io object passed in
+  #
+  # Dump Ruby object +o+ to a YAML string.  Optional +options+ may be passed in
+  # to control the output format.  If an IO object is passed in, the YAML will
+  # be dumped to that IO object.
   #
   # Example:
   #
+  #   # Dump an array, get back a YAML string
   #   Psych.dump(['a', 'b'])  # => "---\n- a\n- b\n"
+  #
+  #   # Dump an array to an IO object
+  #   Psych.dump(['a', 'b'], StringIO.new)  # => #<StringIO:0x000001009d0890>
+  #
+  #   # Dump an array with indentation set
+  #   Psych.dump(['a', ['b']], :indentation => 3) # => "---\n- a\n-  - b\n"
+  #
+  #   # Dump an array to an IO with indentation set
+  #   Psych.dump(['a', ['b']], StringIO.new, :indentation => 3)
   def self.dump o, io = nil, options = {}
     if Hash === io
       options = io
@@ -168,7 +186,7 @@ module Psych
 
     visitor = Psych::Visitors::YAMLTree.new options
     visitor << o
-    visitor.tree.to_yaml io
+    visitor.tree.to_yaml io, options
   end
 
   ###
diff --git a/ext/psych/lib/psych/core_ext.rb b/ext/psych/lib/psych/core_ext.rb
index 8d3e8fb7b6..be26b2f449 100644
--- a/ext/psych/lib/psych/core_ext.rb
+++ b/ext/psych/lib/psych/core_ext.rb
@@ -6,9 +6,10 @@ class Object
   # FIXME: rename this to "to_yaml" when syck is removed
 
   ###
-  # call-seq: to_yaml
+  # call-seq: to_yaml(options = {})
   #
-  # Convert an object to YAML
+  # Convert an object to YAML.  See Psych.dump for more information on the
+  # available +options+.
   def psych_to_yaml options = {}
     Psych.dump self, options
   end
diff --git a/ext/psych/lib/psych/nodes/node.rb b/ext/psych/lib/psych/nodes/node.rb
index 3ab9acae43..bfd91f99ec 100644
--- a/ext/psych/lib/psych/nodes/node.rb
+++ b/ext/psych/lib/psych/nodes/node.rb
@@ -30,10 +30,10 @@ module Psych
       # Convert this node to YAML.
       #
       # See also Psych::Visitors::Emitter
-      def to_yaml io = nil
+      def to_yaml io = nil, options = {}
         real_io = io || StringIO.new
 
-        Visitors::Emitter.new(real_io).accept self
+        Visitors::Emitter.new(real_io, options).accept self
         return real_io.string unless io
         io
       end
diff --git a/ext/psych/lib/psych/visitors/emitter.rb b/ext/psych/lib/psych/visitors/emitter.rb
index 0768fbb528..c84629f9d0 100644
--- a/ext/psych/lib/psych/visitors/emitter.rb
+++ b/ext/psych/lib/psych/visitors/emitter.rb
@@ -1,8 +1,10 @@
 module Psych
   module Visitors
     class Emitter < Psych::Visitors::Visitor
-      def initialize io
+      def initialize io, options = {}
         @handler = Psych::Emitter.new io
+        @handler.indentation = options[:indentation] if options[:indentation]
+        @handler.canonical = options[:canonical] if options[:canonical]
       end
 
       def visit_Psych_Nodes_Stream o